Social Bookmarking Footprints ?

Hello everyone a few days ago I was discussing about how to get updated with new social bookmarking site and someone told me that I should use social bookmarking footprints. I never heard about this one. I even Google it and got the definition that with this you can stay updated with new social bookmarking sites. But I do not know how to use them exactly? So I want to know that what exactly are Social Bookmarking Footprints and how to use them.

Respected admin ! I run a seo team and I need social bookmarking sites on daily basis because old social bookmarking sites have been submitted and now we are running out of social bookmarking sites. That is why it is important for me.

Respected admin ! I run a seo team and I need social bookmarking sites on daily basis because old social bookmarking sites have been submitted and now we are running out of social bookmarking sites. That is why it is important for me.